The present invention relates to a Zn--Ni based composite electroplated steel sheet excellent in various properties such as corrosion resistance and processability The present invention further relates to a multi-layer composite plated steel sheet which comprises said Zn--Ni based composite electroplated steel sheet as a substrate and, provided thereon, a composite film layer mainly composed of SiO.sub.2. More particularly, the present invention relates to a high-corrosion resistant multi-layer composite plated steel sheet which has excellent corrosion resistance, press workability and spot weldability and which is suitable, for example, for rust proofed steel sheet for the automobiles, especially for inner side of bodies.